A retired New York City homicide detective who has helped free two men wrongfully convicted of murder in cases that drew national attention is now investigating the murder conviction of Zachary Witman.

Jay Salpeter said he intends to stay on the case "until we bring him home."

"Zach has spent enough time in jail," he said. "For 15 years, somebody has slept very well knowing Zach's in jail."

Now 29, Witman was 15 when his 13-year-old brother Gregory Witman was brutally attacked inside their New Freedom home on Oct. 2, 1998.

Greg was stabbed and slashed 65 times and nearly decapitated in the family's laundry room, according to police, who said they found bloody gloves and a knife buried in the Witmans' back yard.

Zach Witman was home sick that day. He maintains he was upstairs, heard "roughhousing" downstairs, went down to investigate and found his brother covered in blood.

Private probe: His family and friends have long maintained his innocence, and parents Ron and Sue Witman are now working with Salpeter and others to try to prove it.

Others involved in the private investigation include media expert Lonnie Soury of Soury Communications Inc. in New York City; a local private detective whose name has not been released; and George Matheis Jr., former Aberdeen, Md., police officer and president of Modern Combative Systems LLC in Felton.

Soury described Matheis is an expert in edged weapons.

Salpeter said important new evidence has been found in a number of murder cases he's privately re-investigated. In every one of those cases, it was the creation of a confidential tip line that brought the evidence to light, he said.

In this case, the Witmans said an anonymous donor or donors have put up a $100,000 reward for information that exonerates Zach Witman.

Life sentence: In 2003, Zach Witman was convicted of first-degree murder and sentenced to life in prison without parole.

His case has repeatedly been appealed over the years, but appellate courts have affirmed the conviction.

Four years after the verdict, York County Common Pleas Judge John C. Uhler, who presided at trial, granted Zach Witman a new trial after determining the teen's trial attorney had been ineffective when he allowed prosecutors to enter into evidence a pair of bloody socks that Uhler had previously suppressed.

But prosecutors appealed Uhler's decision and in 2009 the state Superior Court reinstated Witman's conviction.

Overwhelming? The appeals court noted that even if the defense attorney had not allowed prosecutors to present the socks, "the remaining evidence of guilt was overwhelming" and Witman still would have been convicted.

Ron Witman said Wednesday he and his wife don't believe the state Superior Court properly reviewed their son's case.

But at a press conference Wednesday in the Yorktowne Hotel, Salpeter and others expressed grave concerns that the police investigation was shoddy.

"I've been involved in a lot of these types of cases," he said, and most have one common thread - a rush to judgment by police.

"That's exactly what happened here," Salpeter said.

Feels 'let down': Also at the press conference, Ron Witman read aloud a letter from his incarcerated son:

"I still believe that no one deserves to be treated the way I have been by the public and the media," he wrote. "I feel let down by the people of York County ... because they never even gave me a chance."

He wrote he also feels let down by police, prosecutors and the courts.

"What I hope for now is the chance to get out of prison one day," Zach Witman wrote. "I just want the chance to have a decent, meaningful life outside prison."

SCOTUS ruling: Even if Witman's conviction is never overturned, he could eventually be released anyway. That's because the U.S. Supreme Court has ruled it unconstitutional to automatically sentence convicted murder defendants to life in prison without parole if they were juveniles when the murders occurred.

Zach Witman wrote he would rather be freed by exoneration, but will take freedom no matter how it comes.

"We believe that the Pennsylvania Supreme Court should grant Zach a new trial based on ineffective (trial) counsel," Ron Witman said.

"We are very, very confident something will come out of this, and Zach will be released ... and have a life ahead of him," Sue Witman said.

'Nightmare': The grieving mother said there's no fun left in her life, or her husband's life. They visit their son in prison once a week, she said.

"This nightmare will never be over for us," she said. "We lost our most precious gifts -- our children."

She said her sons, who were only 22 months apart, "had a very loving, normal relationship" and spent time together riding bicycles, attending each other's sporting events and camping with their parents.

A number of Witman supporters attended the press conference, including childhood friends Morgan Owens and Terri Spiegel.

"Zach always loved Greg," Spiegel said. "It was obvious."

Owens said she, Zach Witman and their circle of friends didn't drink, didn't use drugs and were serious about school. She said she has "not one doubt" about his innocence.

High-profile cases: It was Sue Witman who first reached out to Salpeter, a retired New York City homicide detective and now a private investigator, according to Ron Witman.

"If you look at his record, (there are) two major national cases in which he was involved (where he) found new evidence - and had people released," Ron Witman said.

Salpeter's work helped lead to the release of one of the West Memphis Three, who spent 18 years in prison for the murders of three little boys in Arkansas.

Salpeter's work also helped overturn the conviction of Martin Tankleff, a Long Island resident wrongfully convicted of murdering his parents. He spent 17 years in prison.

-- Staff writer Liz Evans Scolforo can also be reached at levans@yorkdispatch.com.

CONFIDENTIAL TIP LINE: A $100,000 reward is being offered to the person whose tip leads to the release of Zachary Witman from state prison. The confidential tip line is (717) 819-6006. More information can be found at www.zachwitman.com.